In the 1960s, Vittorio Sereni publishes not only his third and most important poetic collection, Gli strumenti umani, but also one of his greatest prose pieces, L’opzione. The short story first appeared in a journal but was promptly included in a volume, together with some ‘attachments’ among which the poem La pietà ingiusta. Fifteen years later, the two texts, in prose and verse, were republished under the title of Il sabato tedesco, together with the eponymous short story considered by Sereni a follow-up of L’opzione. He therefore recommends reading these texts together. However, when he plans to collect the whole of his narrative pieces, not only does he omit the poem, but he also interposes a third short story, Ventisei, between L’opzione and Il sabato tedesco. This article will explore modifications and adjustments as well as internal references and quotations in order to shed light on Sereni’s attitude towards literary genres. In particular, it will investigate whether the geography of texts, the problem of placement and borders, can reveal something about the relationship between prose and poetry in Sereni’s work.